IEEE 802.17 Resilient Packet Ring Feature Guide

This feature guide describes how to configure the Cisco implementation of the IEEE 802.17 Resilient Packet Ring (RPR) protocol on supported Cisco routers and includes information about the benefits of the feature, supported platforms, related publications, and so on. RPR is similar but not identical to the Spatial Reuse Protocol (SRP), the underlying technology used in the Cisco Dynamic Packet Transfer (DPT) family of products. Throughout this document, this feature is referred to as RPR.

This document covers the use of the RPR feature. It does not include hardware installation and initial configuration information. Refer to the appropriate router installation and configuration note for information on how to configure the hardware and prepare it for use with RPR.

Feature History for RPR

Release

Modification

12.0(29)S

This feature was introduced on the Cisco 10720 Router.

12.0(30)S

The following commands were introduced on the Cisco 10720 Router:

•ping rpr-ieee oam-echo

•rpr-ieee fairness active-weights-detect

•rpr-ieee fairness mode

•rpr-ieee fairness weight

•rpr-ieee protection pref jumbo

•rpr-ieee protection pref wrap

•rpr-ieee tx-traffic strict

The following options were introduced on the Cisco 10720 Router:

•transceiver keyword on the show controllers rpr-ieee command

•history keyword on the show rpr-ieee fairness command

Finding Support Information for Platforms and Cisco IOS Software Images

Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.

Information About RPR

Resilient Packet Ring (RPR), as described in IEEE 802.17, is a metropolitan area network (MAN) technology supporting data transfer among stations interconnected in a dual-ring configuration. This protocol is very similar to Spatial Reuse Protocol (SRP), which was designed by Cisco and implemented in Dynamic Packet Transport (DPT) products. New DPT interfaces have been designed to include the 802.17 RPR protocol and are available for multiple Cisco router platforms. This guide describes the RPR interface and how to use RPR on compliant Cisco equipment.

RPR is a high-speed MAC-layer protocol that is optimized for packet transmission in resilient ring topologies. RPR employs a ring structure using unidirectional, counter-rotating ringlets. Each ringlet is made up of links with data flow in the same direction. The ringlets are identified as ringlet 0 and ringlet 1, as shown in Figure 1. The use of dual fiber-optic rings provides a high level of packet survivability. If a station fails or fiber is cut, data is transmitted over the alternate ring.

Figure 1 Dual-Ring Structure

1

East RX

5

Ringlet 0 data (downstream)

2

West TX

6

Ringlet 0 control (upstream)

3

West RX

7

Ringlet 1 data (downstream)

4

East TX

8

Ringlet 1 control (upstream)

As shown in Figure 1, the east interface of Station 1 (S1) transmits to and receives from the west interface of Station 2 (S2). Ringlet 0 always transverses from east to west and ringlet 1 from west to east. The west span is the span on which RPR transmits on ringlet 1 and the east span is the span on which RPR transmits on ringlet 0.

RPR stations dynamically share the ring bandwidth and permit many simultaneous conversations. Spatial bandwidth reuse is possible due to the packet destination-stripping property of RPR. RPR provides efficient use of available bandwidth by allowing the destination station to remove unicast packets after they are read, thereby providing bandwidth reuse for the other stations on the RPR ring.

While DPT and SRP uses SONET/SDH as the physical medium, IEEE 802.17 RPR has been defined to use both SONET/SDH and the layer used for Gigabit and 10 Gigabit Ethernet.

Comparison of RPR with SRP and DPT Technologies

IEEE 802.17 RPR is very similar to the Cisco-developed SRP technology, which is used in the Cisco DPT product line. Besides their different frame formats, other differences and similarities between IEEE 802.17 RPR and SRP can be summarized as follows:

•Fairness

–IEEE 802.17 RPR has a fairness algorithm that is used in the dynamic SRP-like mode suitable for routing and switching applications.

–A third priority has been added for traffic that requires guaranteed bandwidth, but that is not sensitive to latency and jitter.

•Protection

–SRP supports wrapping.

–IEEE 802.17 RPR supports systems that are capable of steering only protection.

–Cisco-implemented RPR supports both wrapping and steering for protection.

–Wrapping requires two stations to perform protection and suffers the least packet loss.

–Steering requires that every station determines the location of the failure and avoids that particular span. Steering is slower to converge in large topologies versus wrapping.

Configuring the Attribute Discovery Timer

Because station attributes are communicated separately from topology and protection packets, there is a separate timer to control the frequency at which these packets are sent. Attribute propagation is therefore determined by the attribute discovery (ATD) timer. The default rate is 1 packet for each ringlet per second.

To configure the ATD timer, perform the following steps.

Restrictions

Both ringlets are configured with the same value.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee atd-timer seconds

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee atd-timer seconds

Example:

Router(config-if)# rpr-ieeeatd-timer 2

Specifies the time, in seconds, within which one station attributes packet is sent for each ringlet. The default is one packet for each ringlet per second.

Configuring the Clock Source

To configure the clock source for the interface, perform the following steps.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee clock-source {internal | line}[east | west]

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee clock-source {internal | line} [east | west]

Example:

Router(config-if)# rpr-ieee clock-source line east

Specifies the clock source as either line or internal. The default is internal.

Configuring Source Address Tracking

To count packets from a specified source on the ringlet, perform the following steps.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee count src-address

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee count src-address

Example:

Router(config-if)# rpr-ieee count 1.1.1

Counts the number of packets from the specified 48-bit source address (src-address) on the ringlet.

Troubleshooting Tips

Use the show rpr-ieee source-counters command to view the source address counters.

Router# show rpr-ieee source-counters

Source Address Information for Interface RPR-IEEE1/1

0001.0001.0001, index 0, pkt. count 0, byte count 0

0003.0003.0003, index 1, pkt. count 0, byte count 0

Configuring the SONET/SDH Overhead

To configure the SONET/SDH overhead values for the frame header, perform the following steps.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee flag {c2 | j0}value[east | west]

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee flag {c2 | j0} value [east | west]

Example:

Router(config-if)# rpr-ieee flag c2 22 east

Specifies the decimal value for the path signal label (c2) or section trace (j0) SONET/SDH overhead bytes. The default for c2 is 0x16, and the default for j0 is 0x01.

Configuring the SONET Framing

To configure the framing for the packet header and trailer to ensure synchronization and error control, perform the following steps.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee framing {sdh | sonet}[east | west]

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee framing {sdh | sonet} [east | west]

Example:

Router(config-if)# rpr-ieee framing sdh east

Specifies the framing as either SDH or SONET. The default is sonet.

Configuring Loopback Mode

To configure the framer into loopback mode, perform the following steps. This task is for diagnostics only and affects ring operation.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee loopback {internal | line} {east | west}

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee loopback {internal | line} {east | west}

Example:

Router(config-if)# rpr-ieee loopback internal west

Configures the interface in either internal or line loopback mode.

Configuring the Reporting of SONET Alarms

To enable the reporting of information regarding various SONET alarms, perform the following steps.

Specifies the BER threshold value of the specified alarm. The rate value ranges from 3 to 9, thereby representing the bit error rate in the format 10e-n, where n is the rate value. The default is 6 (10e-6) for all thresholds except for sf-ber, where the default is 3 (10e-3).

Configuring Traffic Rates for Transmission

The different priorities of traffic can be configured with rate limiters and prescribed specific bandwidths. This configuration may differ on the east and west spans, or can be configured equally on both. Also, transmitted idle packets can be configured to partake in rate synchronization.

The highest-priority traffic, known as service class A0, can reserve a portion of total ringlet bandwidth using the reserved keyword. This reservation is propagated throughout the ringlet, and all stations recognize the bandwidth allocation cumulatively. Reserved A0 bandwidth can be used only by the station that reserves it. The default allocation is 0 megabits per second.

Service class A1 is configured as high-priority traffic in excess of the A0 bandwidth reservation, and can be rate-limited using the high tx-traffic rate limiter. The default allocation is 10 megabits per second.

The medium transmit traffic rate limiter allows a certain amount of traffic to be added to the ringlet that is not subject to fairness eligibility, but must compete for the unreserved bandwidth with other traffic of the same service class. This traffic is committed information rate (B-CIR) traffic. Some interfaces may not support this class of traffic, so this command may not be available on all RPR interfaces. The default allocation is 10 megabits per second.

The low transmit traffic rate limiter restricts the amount of bandwidth that service classes B-EIR and C may use on the ringlet. This traffic class is fairness eligible and thus this value impacts the effectiveness of the fairness algorithm. The default allocation is full bandwidth.

The idle packet transmitter approximately synchronizes rates between stations by padding traffic with idle packets transmitted at a certain rate. Idle packets are transmitted only to the neighbor, and therefore do not take up transit queue space. If the transit queue vacancy of the local station falls below the configurable idle threshold, fewer idle packets are transmitted by the local station to give more transmit time to drain the queue. This rate synchronization is used in the extreme congestion case to prevent packet drops in the transit queue.

Traffic can be specified to be in strict or relaxed mode. Relaxed mode does not flush (drop) traffic in case of a protection event, such as a fiber failure. As a result, there is less traffic loss but a slight possibility of re-ordering packets during a node recovery. Relaxed mode is the default traffic mode. Strict mode flushes traffic after a topology change, such as a protection event, until the topology stabilizes.

Specifies a rate limit on a traffic queue. The allowable rate depends on the speed of the interface.

reserved—Reserves bandwidth for the highest priority traffic, known as service class A0. The default allocation is 0 Mbps.

high—Limits the rate of service class A1. The default allocation is 10 Mbps.

medium—Limits the rate of service class B-CIR. The default allocation is 10 Mbps.

low—Limits the rate of service classes B-EIR and C. The default allocation is full bandwidth.

Step 5

rpr-ieee tx-traffic idle {enable | threshold threshold}

Example:

Router(config-if)# rpr-ieee tx-traffic idle threshold 10000

Specifies the behavior of the idle packet transmission.

enable—Determines whether any idle packets are sent at all. The default operation is enabled.

threshold—Specifies the transit queue vacancy under which fewer idle packets are transmitted, allowing for the transit queue to drain faster. A higher threshold allows the idle packet transmit behavior to change sooner. The default vacancy threshold is one MTU.

Troubleshooting Tips

Use the show rpr-ieee rate-limit command to view the configured values for the rate manipulators on the various classes of traffic. There are rate limiters for classes A0 (or reserved), A1, B-CIR, and B-EIR and C. Some interfaces don't support class B on transmit, so only the other three are displayed.

Following is sample output from the show rpr-ieee rate-limit command:

Router# show rpr-ieee rate-limit

Rate Limit Information for Interface RPR-IEEE1/1

West Span:

Reserved Bandwidth (Class A0): 0 Mbps

Rate Limiter High (Class A1): 10 Mbps

Rate Limiter Medium (Class B-CIR): 10 Mbps

Rate Limiter Low (Class B-EIR, C): 2488 Mbps

East Span:

Reserved Bandwidth (Class A0): 0 Mbps

Rate Limiter High (Class A1): 10 Mbps

Rate Limiter Medium (Class B-CIR): 10 Mbps

Rate Limiter Low (Class B-EIR, C): 2488 Mbps

Following is sample output from the show rpr-ieee rate-limit command when no low rate limit is configured. In this instance, full is shown. This is equivalent to having a rate limit of 2488 Mbps configured on an OC48 link.

Router# show rpr-ieee rate-limit

West Span:

Reserved Bandwidth (Class A0): 0 Mbps

Rate Limiter High (Class A1): 10 Mbps

Rate Limiter Medium (Class B-CIR): 10 Mbps

Rate Limiter Low (Class B-EIR, C): full

Use the details keyword to display the idle packet transmission configuration, as shown in the following example:

router# show rpr-ieee rate-limit details

Rate Limit Information for Interface RPR-IEEE1/1

West Span:

Reserved Bandwidth (Class A0): 0 Mbps

Rate Limiter High (Class A1): 10 Mbps

Rate Limiter Medium (Class B-CIR): 10 Mbps

Rate Limiter Low (Class B-EIR, C): 2488 Mbps

East Span:

Reserved Bandwidth (Class A0): 0 Mbps

Rate Limiter High (Class A1): 10 Mbps

Rate Limiter Medium (Class B-CIR): 10 Mbps

Rate Limiter Low (Class B-EIR, C): 2488 Mbps

Service Type: Relaxed

Idle Shaper is Enabled

Transmit at 500 packets per million when PTQ vacancy above 18432 bytes

Transmit at 250 packets per million when PTQ vacancy below 18432 bytes

How to Configure RPR Fairness

A larger enhancement of RPR over DPT is its configurable fairness system, used to control congestion on each ringlet. This feature moderates bandwidth utilization of the ringlet to minimize and potentially eliminate starvation of any station. Each station has two instances of the fairness machine, to control traffic that is being transmitted and transited out of each span of the interface. Each fairness machine is devoted to a particular ringlet, and controls the traffic that is destined to that ringlet.

Fairness is configured in the west and east directions independently. Each ringlet in an unwrapped ring is independent, and thus the fairness configuration can differ for each direction.

Configuring Active Weights

IEEE 802.17 fairness is a weighted process for negotiating fair rates. By default, all weights are set to the lowest possible value (1), and this results in equal-weight fairness. If any station is configured with a higher weight, then weighted fairness is activated. In aggressive fairness mode, this happens automatically and a station uses its own weight to determine the fair transmission rate. In conservative fairness mode, the station uses its own weight and weights detected from upstream stations to determine its fair transmission rate. If you do not want conservative fairness mode to use detected weights in the fair-rate calculation, you can disable the active-weight detection (which is enabled by default). Active-weight detection affects only conservative fairness mode when weights are not set to their lowest value.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee fairness active-weights-detect [east | west]

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee fairness active-weights-detect [east | west]

Example:

Router(config-if)# rpr-ieee fairness active-weight-detect east

Enables the calculation of ringlet weights from stations that have recently contributed traffic over a configurable interval from the specified direction. Use the no form of this command to disable active-weights.

Configuring Fairness Rate Adjustments

The fairness rate adjustment method can be changed to one of two modes. Only one mode is selectable at a time on an interface. Switching between modes can be disruptive to traffic because it requires that the fairness machine completely restart with new initial values. Aggressive and conservative stations can be configured on the same ringlet, but more consistent operation results from using one or the other on every station. Aggressive rate adjustment is the default setting.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee fairness mode {aggressive | conservative}

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee fairness mode {aggressive | conservative}

Example:

Router(config-if)# rpr-ieee fairness mode conservative

Specifies the fairness rate adjustment method. The default is aggressive.

Configuring Multichoke Fairness

Multichoke fairness enables enhanced fairness beyond a single congestion point. This feature may not be supported on all platforms and is optional in the 802.17 standard. It is disabled by default.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee fairness multi-choke

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee fairness multi-choke

Example:

Router(config-if)# rpr-ieee fairness multi-choke east

Enables multichoke fairness. It is disabled by default. Use the no form of this command to disable multichoke fairness.

Configuring Fairness Weights

The local station weight impacts how congested the station appears with respect to other stations in the ringlet. It also affects how much more bandwidth a station may use over other stations in the ring. A higher weight tends to result in giving the local station more than its fair share of ringlet bandwidth compared with its neighbors. Lower weights tend to result in less bandwidth demand from the local station. The default value is 0 configured as an exponent of 2, which yields an effective weight of 1.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee fairness weight weight[east | west]

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee fairness weight weight [east | west]

Example:

Router(config-if)# rpr-ieee fairness weight 6 east

Specifies the weight for a station on the ringlet. Values can range from 0 to 7, which are configured as an exponent of 2, thereby yielding weights ranging from 1 to 128.

Troubleshooting Tips

To view the fairness information, use the show rpr-ieee fairness command. The fairness system uses a large quantity of input to determine its behavior. This input and some results of the fairness algorithm can be displayed. Information for both directions is always shown. The following example shows what would be seen on an OC-48 interface employing aggressive rate adjustment, with no multichoke fairness.

Router# show rpr-ieee fairness

IEEE 802.17 Fairness on RPR-IEEE1/1:

Bandwidth: 2488320 kilobits per second

Station using aggressive rate adjustment.

Westbound Tx (Ringlet 1)

Weighted Fairness:

Local Weight: 0 (1)

Single-Choke Fairness Status:

Local Congestion:

Congested? No

Head? No

Downstream Congestion:

Congested? No

Tail? No

Received Source Address: 0001.0001.0001

Reserved Rate:

0 Kbps

Unreserved Rate:

2488320 Kbps

Eastbound Tx (Ringlet 0)

Weighted Fairness:

Local Weight: 0 (1)

Single-Choke Fairness Status:

Local Congestion:

Congested? No

Head? No

Downstream Congestion:

Congested? No

Tail? No

Received Source Address: 0003.0003.0003

Reserved Rate:

0 Kbps

Unreserved Rate:

2488320 Kbps

This information can also be viewed in a more detailed form by using the details keyword. The additional information includes the coefficients used, more expressions of the configured and detected rates, and transit queue information.

How to Configure RPR Protection

RPR includes steering and wrapping protection. A number of tasks can be used to configure the protection capabilities:

Configuring the Hold-off Timer

A protection response to Layer 1 failure events (such as a signal failure or signal degradation) can be delayed by configuring the hold-off timer. A higher value for this timer causes a protection response to be delayed, avoiding link errors that persist long enough to be detected by protection but short enough to avoid costs of protecting the span. This delay can result in higher traffic loss, however. The default value for this timer is 0 milliseconds.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee protection sonet holdoff-timer time [east | west]

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee protection sonet holdoff-timer time [east | west]

Example:

Router(config-if)# rpr-ieee protection holdoff-timer 5 west

Specifies the delay before a protection response is sent. Values range from 0 to 20, in units of 10 milliseconds. The default is 0.

Configuring Protection Preferences

The interface can be configured to support jumbo frames and wrapping. These commands are not mutually exclusive.

The jumbo setting specifies that the station support an MTU of up to 9100 bytes. To be enabled, all stations on the ring must be set to support jumbo frames. The wrap setting specifies that by default the station use wrapping instead of steering.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee protection pref {jumbo | wrap}

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee protection pref{jumbo | wrap}

Example:

Router(config-if)# rpr-ieee protection pref wrap

Enables jumbo frames or wrap-capability on the interface:

jumbo—Enables handling of frames in excess of the standard 1500 bytes, up to a maximum size of 9100 bytes. A jumbo-enabled station changes the interface MTU to 9100 bytes only if all stations in the ring are jumbo enabled. This option is disabled by default. A message is generated to indicate that the ring supports jumbo frames when all stations are configured for this preference.

wrap—Makes stations use wrapping protection instead of steering, as long as conditions permit. Although a station that is wrap capable uses wrapping regardless of the settings of other stations on the ring, it is critical that all stations be configured for the same protection preference (wrapping or steering) for traffic protection to operate correctly. An alarm message is issued if protection preferences differ between stations on the ring. This option is disabled by default to prefer steering.

Configuring Forced or Manual Switching

You can request certain protection states to take effect manually on either span of the interface, to avoid link usage or in anticipation of failures.

forced-switch—Precedes all other failure events on a ring, for the span on which it is configured. The operation protects the span indicated by the command. In the case of steering, forwarding uses only the topology list for the opposite span. In the case of wrapping, the other span becomes wrapped. A forced switch is saved in the configuration.

manual-switch—Behaves similarly to a forced switch, in that it coerces a reaction from the protection system. The difference is that this configuration can be usurped by higher-level requests detected on the configured or the opposite span. A manual switch is not saved in the configuration.

Configuring SONET Protection

For SONET-based devices, RPR can set the threshold at which a protection event occurs for a signal failure or signal degradation (sf-ber or sd-ber).

Specifies the threshold at which a signal degradation or signal failure is triggered. The threshold values represent the bit error rate as 10 to the minus threshold, where threshold ranges from 4 to 9.

Configuring Protection Timers

Protection messages are sent based on the intervals of two timers. These timers apply under different circumstances:

•Fast timer—Immediately after a protection event occurs, a fast protection timer is used. This timer is configured between 1 and 20 milliseconds to cause a rapid acknowledgement of the protected state on the ring. A finite number of packets are sent at this frequency after the event. The default for this timer is 10 milliseconds.

•Slow timer—Between protection events, the slow timer communicates the current protection state of the ring. This timer is configured from 1 to 10 in units of 100 milliseconds. The default is 10, which represents 100 milliseconds.

The protection timers are configured the same on both spans of an interface.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee protection timer {fast time| slow time}

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee protection timer {fast time| slow time}

Example:

Router(config-if)# rpr-ieee protection timer fast 10

Specifies the value of the fast or slow protection timer.

fast—Ranges from 1 to 20 milliseconds. The default is 10.

slow—Ranges from 1 to 10 in units of 100 milliseconds. The default is 1 (100 milliseconds).

Configuring the Wait-to-Restore Timer

When a failure is de-asserted on a span, a wait-to-restore timer defines how long before the span becomes unprotected. This timer can be used to protect against false negatives in the detection of the failure status, and thus avoid protection-flapping by using larger values. Smaller values result in faster recovery times, however. This timer can be configured between 0 and 1440 seconds, or configured to not recover automatically at all. The default for the timer is 10 seconds.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee protection wtr-timer {time| never}

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee protection wtr-timer {time| never}

Example:

Router(config-if)# rpr-ieee protection wtr-timer 20

Specifies the value of the wait-to-restore timer:

time—Ranges from 0 to 1440 seconds. The default is 10.

never—Specifies that protection is never restored (nonrevertive mode).

Protection Troubleshooting Tips

To verify the protection configurations, use the show rpr-ieee protection command. Following is sample output from this command:

Router# show rpr-ieee protection

Protection Information for Interface RPR-IEEE1/1

MAC Addresses

West Span (Ringlet 0 RX) neighbor 0001.0001.0001

East Span (Ringlet 1 RX) neighbor 0003.0003.0003

Station MAC address 0002.0002.0002

TP frame sending timers:

fast timer: 10 msec

slow timer: 1x100 msec (100 msec)

Protection holdoff timers:

L1 Holdoff Keepalive Detection

West Span 0x10 msec ( 0 msec) West Span 3 msec

East Span 0x10 msec ( 0 msec) East Span 3 msec

Configured protection mode: STEERING

Protection Status

Ring is IDLE

Protection WTR period is 10 sec. (timer is inactive)

Self Detected Requests Remote Requests

West Span IDLE West Span IDLE

East Span IDLE East Span IDLE

Distant Requests

East Span IDLE West Span IDLE

West Span Failures: none

East Span Failures: none

Shutting Down a Span

To cause a forced switch on the span of the interface, perform the following steps. The rpr-ieee shutdown command performs the same task as the rpr-ieee protection request forced-switch command.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee shutdown {east | west}

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee shutdown {east | west}

Example:

Router(config-if)# rpr-ieee shutdown west

Causes a forced switch on a span of the interface.

Configuring Keepalive Events

A station can determine whether a link is alive if it is receiving fairness messages from it. This feature is independent of the fairness algorithm itself, but is nonetheless a function performed by the fairness machine. The number of milliseconds that pass without receiving a fairness message from the neighboring stations is measured. When this time exceeds a configured timeout, then a keepalive event is triggered, which generates a protection event. The timer may have a different value on either span. The keepalive timer should be configured greater than or equal to the hold-off timer. The default keepalive timer is 3 milliseconds.

SUMMARY STEPS

1. enable

2. configureterminal

3. interface rpr-ieeeslot/port

4. rpr-ieee keepalive-timer time [east | west]

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Enters interface configuration mode for a specific RPR interface.

Step 4

rpr-ieee keepalive-timer time [east | west]

Example:

Router(config-if)# rpr-ieee keepalive-timer 5 west

Specifies the amount of time that can pass before a keepalive event is triggered after not receiving a fairness message from a neighboring station. Values range from 2 to 200 milliseconds. The default is 3.

How to Use Modular QoS CLI to Configure RPR Service Classes

Layer 3 prioritized traffic is directed to the three service classes supported by RPR by using the Modular QoS CLI (MQC). MQC is a CLI structure that allows you to create traffic policies and attach these policies to interfaces. A traffic policy contains a traffic class and one or more QoS features. A traffic class classifies traffic, while the QoS features in the traffic policy determine how to treat the classified traffic.

SUMMARY STEPS

1. enable

2. configureterminal

3. class-map match-anyclass-name

4. match ip precedencenumber

5. exit

6. policy-mappolicy-name

7. classclass-name

8. shaperate

9. set rpr-ieee service-class {a | b | c}

10. exit

11. exit

12. interface rpr-ieeeslot/port

13. service-policy outputpolicy-name

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

class-map match-any class-name

Example:

Router(config)# class-map match-any RPR_A

Specifies the user-defined name of the traffic class and the logical OR operator for all matching statements under this traffic class.

Step 4

match ip precedence number

Example:

Router(config-cmap)# match ip precedence 6 7

Specifies up to eight IP precedence values (0 to 7) used as match criteria.

For RPR, class maps link Layer 3 precedences to MQC classes. For IP version 4, there are eight priority levels that must be mapped. The example shows the configuration of three class maps corresponding to the three RPR service classes.

Step 5

exit

Example:

Router(config-pmap-c)# exit

Exits class mode.

Step 6

policy-map policy-name

Example:

Router(config)# policy-map RPR_class

Specifies the name of the service policy to configure. Service policies link the configured class maps to Layer 2 traffic priorities, or in this case, the three service classes of RPR. An assignment has to be constructed for each class map.

Step 7

class class-name

Example:

Router(config-pmap)# class RPR_A

Specifies the name of a predefined class, which was defined with the class-map command, to be included in the service policy.

Note Each of the three RPR classes must be configured as described in this procedure.

Step 8

shape rate

Example:

Router(config-pmap-c)# shape 2488320

When configuring RPR traffic classes, the shape or bandwidth command must be used. If the shape command is set to full line rate, as in this example, then only RPR queue control (fairness and rate limits) affects the transmission rate. If a lower value for a shape or a bandwidth value is used, the impact of the RPR queue control on transmit is altered. The two applications take effect in series.

The rate is in Kbps.

Step 9

set rpr-ieee service-class {a | b | c}

Example:

Router(config-pmap-c)# set rpr-ieee service-class guaranteed

Specifies the appropriate RPR service class for the class. The three classes correspond to each of the three RPR service classes. Only one service class can be configured for each MQC class.

Step 10

exit

Example:

Router(config-pmap-c)# exit

Exits class mode.

Step 11

exit

Example:

Router(config-pmap)# exit

Exits policy map mode.

Step 12

interface rpr-ieeeslot/port

Example:

Router(config)# interface rpr-ieee2/0

Specifies the RPR interface to which to attach the configured service policy.

Step 13

service-policy output policy-name

Example:

Router(config-if)# service-policy output RPR_Class

Attaches the configured service policy to the RPR interface.

Configuration Example Using MQC to Configure RPR Service Classes

Following is an example of the entire configuration process for the three RPR service classes:

class-map match-any RPR_A

match ip precedence 6 7

class-map match-any RPR_B

match ip precedence 4 5

class-map match-any RPR_C

match ip precedence 0 1 2 3

policy-map RPR_CLASS

class RPR_A

shape 2488320

set rpr-ieee service-class a

class RPR_B

shape 2488320

set rpr-ieee service-class b

class RPR_C

shape 2488320

set rpr-ieee service-class c

interface rpr-ieee1/1

service-policy output RPR_CLASS

Troubleshooting Tips

To verify the service class configurations, use the following commands:

Command

Purpose

Router# showpolicy-map class-name

Displays the configuration of the specified class.

Router# showpolicy-map interfaces rpr-ieee slot/port

Displays statistics for the class on a specific interface and the number of packets sent to each service class of the interface.

Following is sample output from the show policy-map command:

Router# show policy-map RPR_CLASS

Policy Map RPR_CLASS

Class RPR_A

shape 2488320

set rpr-ieee service-class a

Class RPR_B

shape 2483320

set rpr-ieee service-class b

Class RPR_C

shape 2488320

set rpr-ieee service-class c

Following is sample output from the show policy-map interfaces command:

Router# show policy-map interfaces rpr-ieee1/1

Service-policy output: RPR_CLASS (1047)

Class-map: RPR_A (match-any) (1083/4)

0 packets, 0 bytes

5 minute offered rate 0 bps, drop rate 0 bps

Match: ip precedence 6 7 (1084)

shape (VCCI 2->side E): 2488320 kbps

shape (VCCI 3->side W): 2488320 kbps

QoS Set

rpr-ieee service-class a

Packets marked 0

Class-map: RPR_B (match-any) (1105/5)

0 packets, 0 bytes

5 minute offered rate 0 bps, drop rate 0 bps

Match: ip precedence 4 5 (1106)

shape (VCCI 2->side E): 2481023 kbps

shape (VCCI 3->side W): 2481023 kbps

QoS Set

rpr-ieee service-class b

Packets marked 0

Class-map: RPR_C (match-any) (1122/6)

0 packets, 0 bytes

5 minute offered rate 0 bps, drop rate 0 bps

Match: ip precedence 0 1 2 3 (1123)

shape (VCCI 2->side E): 2488320 kbps

shape (VCCI 3->side W): 2488320 kbps

QoS Set

rpr-ieee service-class c

Packets marked 0

Class-map: class-default (match-any) (1059/0)

0 packets, 0 bytes

5 minute offered rate 0 bps, drop rate 0 bps

Match: any (1060)

0 packets, 0 bytes

5 minute rate 0 bps

How to Verify RPR Configuration and Operation

To verify RPR configuration and operation, perform the following tasks:

Viewing Traffic Counters

Traffic counters are collected from various sources in the interface, and are displayed using the show rpr-ieee counters command. This command shows received, transited, and transmitted quantities of each of the various service classes, and on each span. Receive errors are also indicated for each span. Following is sample output from the show rpr-ieee counters command:

Router# show rpr-ieee counters

Data Traffic Counters for Interface RPR-IEEE1/1

WEST Span:

Transit Packets Bytes

Total Low Priority 0 0

Total Med EIR Priority 0 0

Total Med CIR+EIR Priority 0 0

Total High Priority 0 0

Total Multicast 0 0

Total Unicast 0 0

Host Receive Packets Bytes

Unicast Low Priority 0 0

Unicast Med EIR Priority 0 0

Unicast Med CIR Priority 0 0

Unicast High Priority 0 0

Multicast Low Priority 0 0

Multicast Med EIR Priority 0 0

Multicast Med CIR Priority 0 0

Multicast High Priority 0 0

Total Receive Packets Bytes

Unicast Low Priority 0 0

Unicast Med EIR Priority 0 0

Unicast Med CIR Priority 0 0

Unicast High Priority 0 0

Multicast Low Priority 0 0

Multicast Med EIR Priority 0 0

Multicast Med CIR Priority 0 0

Multicast High Priority 0 0

Host Transmit Packets Bytes

Unicast Low Priority 0 0

Unicast Med EIR Priority 0 0

Unicast Med CIR Priority 0 0

Unicast High Priority 0 0

Multicast Low Priority 0 0

Multicast Med EIR Priority 0 0

Multicast Med CIR Priority 0 0

Multicast High Priority 0 0

Total Transmit Packets Bytes

Unicast Low Priority 0 0

Unicast Med EIR Priority 0 0

Unicast Med CIR Priority 0 0

Unicast High Priority 0 0

Multicast Low Priority 0 0

Multicast Med EIR Priority 0 0

Multicast Med CIR Priority 0 0

Multicast High Priority 0 0

Traffic Rate (5 Minutes) packets/sec bits/sec

Transit Low Priority 0 0

Transit Med EIR Priority 0 0

Transit Med CIR+EIR Priority 0 0

Transit High Priority 0 0

Transit Multicast 0 0

Transit Unicast 0 0

Host Receive 0 0

Total Receive 0 0

Host Transmit 0 0

Total Transmit 0 0

Received Errors:

0 input errors, 0 CRC, 0 ignored,

0 framer runts, 0 framer giants, 0 framer aborts,

0 mac runts, 0 mac giants, 0 mac ttl strips,

0 non-we drop

EAST Span:

Transit Packets Bytes

Total Low Priority 0 0

Total Med EIR Priority 0 0

Total Med CIR+EIR Priority 0 0

Total High Priority 0 0

Total Multicast 0 0

Total Unicast 0 0

Host Receive Packets Bytes

Unicast Low Priority 0 0

Unicast Med EIR Priority 0 0

Unicast Med CIR Priority 0 0

Unicast High Priority 0 0

Multicast Low Priority 0 0

Multicast Med EIR Priority 0 0

Multicast Med CIR Priority 0 0

Multicast High Priority 0 0

Total Receive Packets Bytes

Unicast Low Priority 0 0

Unicast Med EIR Priority 0 0

Unicast Med CIR Priority 0 0

Unicast High Priority 0 0

Multicast Low Priority 0 0

Multicast Med EIR Priority 0 0

Multicast Med CIR Priority 0 0

Multicast High Priority 0 0

Host Transmit Packets Bytes

Unicast Low Priority 0 0

Unicast Med EIR Priority 0 0

Unicast Med CIR Priority 0 0

Unicast High Priority 0 0

Multicast Low Priority 0 0

Multicast Med EIR Priority 0 0

Multicast Med CIR Priority 0 0

Multicast High Priority 0 0

Total Transmit Packets Bytes

Unicast Low Priority 0 0

Unicast Med EIR Priority 0 0

Unicast Med CIR Priority 0 0

Unicast High Priority 0 0

Multicast Low Priority 0 0

Multicast Med EIR Priority 0 0

Multicast Med CIR Priority 0 0

Multicast High Priority 0 0

Traffic Rate (5 Minutes) packets/sec bits/sec

Transit Low Priority 0 0

Transit Med EIR Priority 0 0

Transit Med CIR+EIR Priority 0 0

Transit High Priority 0 0

Transit Multicast 0 0

Transit Unicast 0 0

Host Receive 0 0

Total Receive 0 0

Host Transmit 0 0

Total Transmit 0 0

Received Errors:

0 input errors, 0 CRC, 0 ignored,

0 framer runts, 0 framer giants, 0 framer aborts,

0 mac runts, 0 mac giants, 0 mac ttl strips,

0 non-we drop

Viewing Failures

The show rpr-ieee failures command displays all input used to determine the failure state of each span of the interface. This information can be used to debug the cause of a protection event. Following is sample output from this command:

Router# show rpr-ieee failures

Self Detected Failures Information for Interface RPR-IEEE1/1

Span WEST:

Reported Debounced Current Stable Debounce

state state state for(sec) delay(sec)

HW missing IDLE IDLE IDLE 22641 0

Layer 1 IDLE IDLE IDLE 22629 0

MAC Keepalive IDLE IDLE IDLE 22640 10

Link quality IDLE IDLE IDLE 22641 0

Mate interface IDLE IDLE IDLE 22641 10

Span mismatch IDLE IDLE IDLE 22641 0

Result Self Detect = IDLE

Span EAST:

Reported Debounced Current Stable Debounce

state state state for(sec) delay(sec)

HW missing IDLE IDLE IDLE 22641 0

Layer 1 IDLE IDLE IDLE 22630 0

MAC Keepalive IDLE IDLE IDLE 22640 10

Link quality IDLE IDLE IDLE 22641 0

Mate interface IDLE IDLE IDLE 22642 10

Span mismatch IDLE IDLE IDLE 22642 0

Result Self Detect = IDLE

Viewing the RPR Topology

The show rpr-ieee topology command provides information on the local station, its neighbors, and the general state of the ring. Packets sent to communicate topology information are constructed using data from various sources, such as the configured preferences, cumulative reserved bandwidth, protection states, and station name. This information is displayed for the local station and every active station from which a topology message has been received.

Following is sample output from the show rpr-ieee topology command:

Router# show rpr-ieee topology

Ring Topology: CLOSED (STABLE)

Configured protection mode: WRAPPING

Jumbo preference: SET (ring supports JUMBOS)

Number of nodes on

ringlet0: 3 ringlet1: 3

Checksum: 0x001800D6

Index (Ri 0) MAC IP Address Edge W/E Request W/E

1 0001.0001.0001 1.1.1.1 NO/NO IDLE/IDLE

2 0003.0003.0003 1.1.1.3 NO/NO IDLE/IDLE

3 0002.0002.0002 1.1.1.2 NO/NO IDLE/IDLE

Index (Ri 1) MAC IP Address Edge W/E Request W/E

1 0003.0003.0003 1.1.1.3 NO/NO IDLE/IDLE

2 0001.0001.0001 1.1.1.1 NO/NO IDLE/IDLE

3 0002.0002.0002 1.1.1.2 NO/NO IDLE/IDLE

Following is sample output from the show rpr-ieee topology details command:

MIBs

Technical Assistance

Description

Link

Technical Assistance Center (TAC) home page, containing 30,000 pages of searchable technical content, including links to products, technologies, solutions, technical tips, and tools. Registered Cisco.com users can log in from this page to access even more content.

Syntax Description

(Optional) Specifies the chassis slot number and port number of a specific RPR interface.

dest-address

Specifies the 48-bit destination address to which to send the 802.17 echo, in the format H.H.H.

r0 | r1

Specifies to send the request on either ringlet 0 (r0), or ringlet 1 (r1).

r0 | r1 | rev

Specifies to send the response on ringlet 0 (r0), ringlet 1 (r1), or the opposite ringlet to which the request was sent (rev).

count

Specifies the number of times to repeat the request, up to 1000 times. If not specified, the request is done once.

timeout

Specifies the timeout in seconds, after which to abort the request. The timeout can be from 0 to 30 seconds. The default timeout is 2 seconds.

Defaults

count: 1timeout: 2 seconds

Command Modes

Privileged EXEC

Command History

Release

Modification

12.0(30)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

This command performs an 802.17 Echo, which is basically a Layer 2 ping. It is independent of any Layer 3 configuration and is designed to test ring connectivity in the absence of any upper layers. The command uses specific 802.17 control packets designed for the purpose. The command allows you to test each ringlet to each station independently and thereby verify all Layer 2 connections.

If you enter the ping command without any other syntax (ping<cr>), the CLI displays an interactive system dialog that prompts you for the additional syntax appropriate to the protocol you specify (See the "Examples" section).

To exit the interactive ping dialog before responding to all prompts, type the escape sequence. The default escape sequence is Ctrl-^,X (simultaneously press and release the Ctrl, Shift, and 6 keys and then press the X key). The escape sequence varies depending on your line configuration. For example, another commonly used escape sequence is Ctrl-c.

rpr-ieee atd-timer

To configure the attribute discovery timer (ATD), use the rpr-ieee atd-timer command in interface configuration mode. To restore the default timer value, use the no form of this command.

rpr-ieee atd-timer seconds

no rpr-ieee atd-timer

Syntax Description

seconds

Specifies the time, in seconds, within which one station attributes packet is sent for each ringlet. The default is one packet for each ringlet per second.

Defaults

1 second

Command Modes

Interface configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

Use this command to configure the attribute discovery timer. Because station attributes are communicated separately from topology and protection packets, there is a separate timer to control the frequency at which these packets are sent. Attribute propagation is therefore determined by the ATD timer. Both ringlets are configured with the same value.

rpr-ieee clock-source

To configure the clock source, use therpr-ieee clock-sourceinterface configuration command. To restore the default clock source, use the no form of this command.

rpr-ieee clock-source{line | internal} [east | west]

no rpr-ieee clock-source[east | west]

Syntax Description

line

Specifies the clock source as line. Use this option when connecting a router to SONET/SDH ADM.

internal

Specifies the clock source as internal. Use this option when connecting between two routers over dark fiber or over a Wavelength Division Multiplexing (WDM) system.

east

(Optional) Specifies that the configuration is for the east span. If no span is specified, the configuration is set for both the east and west spans.

west

(Optional) Specifies that the configuration is for the west span.

Defaults

Internal

Command Modes

Interface configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

When you configure a connection between two Cisco 10700 Series Routers, you can configure the RPR interfaces for the clock source as follows:

•You can set either span on a single station to internal (default) or line.

•You cannot set both ends on a specific span (between neighbors) to line.

You can configure the RPR interface on one side of the connection as internal and the RPR interface on the other side as line. This configuration is available for installations in which line timing is desirable, such as Add/Drop Multiplexer (ADM) and Wavelength Division Multiplexing (WDM).

Related Commands

rpr-ieee fairness active-weights-detect

To enable the calculation of ringlet weights from stations that have recently contributed traffic over a configurable interval from the specified direction, use the rpr-ieee fairness active-weights-detect command in interface configuration mode. To disable the use of these weights, use the no form of this command.

rpr-ieee fairness active-weights-detect [east | west]

no rpr-ieee fairness active-weights-detect [east | west]

Syntax Description

east

(Optional) Specifies that the configuration is for the east span. If no span is specified, the configuration is set for both the east and west spans.

west

(Optional) Specifies that the configuration is for the west span.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release

Modification

12.0(30)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

IEEE 802.17 fairness is a weighted process for negotiating fair rates. Disabling equal-weight fairness is done by configuring the lowest weight for the local station, and disabling active-weights-detect. Disabling equal-weight fairness removes any effect of weights from both the rate adjustment process, and also from the rates advertised to neighbors. When active-weights is enabled, however, it allows for the calculation of ringlet weights from stations that have recently contributed traffic.

Examples

The following example shows how to enable the calculation of ringlet weights on the east span:

rpr-ieee fairness mode

Syntax Description

aggressive

Uses the default ramp rate for the fairness algorithm. Aggressive mode ramps up as quickly as possible when bandwidth is available and ramps down as quickly as possible when congestion occurs. This fast ramping can result in unstable traffic behavior in very bursty traffic scenarios.

conservative

Uses the optional ramp rate for the fairness algorithm. Conservative mode ramps up in stages (over a few hundred milliseconds) when bandwidth is available and ramps down in stages (over a few hundred milliseconds) when congestion occurs. This slower ramping can result in slightly lower bandwidth utilization, but is more applicable in very bursty traffic scenarios.

Defaults

Aggressive

Command Modes

Interface configuration

Command History

Release

Modification

12.0(30)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

The fairness rate adjustment method can be changed to one of two modes. Only one mode is selectable at a time for either direction. Switching between modes can be disruptive to traffic because it requires that the fairness machine completely restart with new initial values. Aggressive and conservative stations can be configured on the same ringlet, but more consistent operation results from using one or the other on every station.

Examples

The following example shows how to enable aggressive ramping for the fairness algorithm:

Examples

Related Commands

Displays the fairness settings and some results of the fairness algorithm.

rpr-ieee fairness weight

To specify the weight for a station on an RPR ringlet, use the rpr-ieee fairness weight command in interface configuration mode. To restore the default fairness weight, use the no form of this command.

rpr-ieee fairness weight weight [east | west]

no rpr-ieee fairness weight weight [east | west]

Syntax Description

weight

Specifies the weight for a station on the ringlet. Values can range from 0 to 7, which are configured as an exponent of 2, thereby yielding weights ranging from 1 to 128.

east

(Optional) Specifies that the configuration is for the east span. If no span is specified, the configuration is set for both the east and west spans.

west

(Optional) Specifies that the configuration is for the west span.

Defaults

0

Command Modes

Interface configuration

Command History

Release

Modification

12.0(30)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

The weight of the local station impacts how congested the station appears with respect to other stations in the ringlet. It also affects how much more bandwidth a station may use over other stations in the ring. A higher weight tends to result in giving the local station more than its fair share of ringlet bandwidth compared with its neighbors. A lower weight tends to result in less bandwidth demand from the local station. The default is 0 configured as an exponent of 2, which yields an effective weight of 1.

Examples

The following example shows how to set the weight of the east span to be 26 or 64:

Related Commands

Specifies framing for the packet header and trailer to ensure synchronization and error control.

rpr-ieee framing

To specify framing for the packet header and trailer to ensure synchronization and error control, use the rpr-ieeeframing command in interface configuration mode. To restore the default framing, use the no form of this command.

rpr-ieee framing {sdh | sonet} [east| west]

no rpr-ieee framing {sdh | sonet} [east| west]

Syntax Description

sdh

Specifies SDH framing and s1s0=2

sonet

Specifies SONET framing and s1s0=0 (default)

east

(Optional) Specifies that the configuration is for the east span. If no span is specified, the configuration is set for both the east and west spans.

west

(Optional) Specifies that the configuration is for the west span.

Defaults

sonet

Command Modes

Interface configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

Examples

The following example sets the framing to SDH on both the east and west spans:

Router(config-if)# rpr-ieee framing sdh

Related Commands

rpr-ieee keepalive-timer

To configure the amount of time to wait before a keepalive event is triggered on an RPR interface, use the rpr-ieee keepalive-timer command in interface configuration mode. To restore the default timer value, use the no form of this command.

rpr-ieee keepalive-timer time [east | west]

no rpr-ieee keepalive-timer time [east | west]

Syntax Description

time

Specifies an amount of time in milliseconds that can pass before a keepalive event is triggered after not receiving a fairness message from a neighboring station. Values range from 2 to 200 milliseconds.

east

(Optional) Specifies that the configuration is for the east span. If no span is specified, the configuration is set for both the east and west spans.

west

(Optional) Specifies that the configuration is for the west span.

Defaults

3 milliseconds

Command Modes

Interface configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

A station can determine whether a link is alive if it is receiving fairness messages from it. This feature is independent of the fairness algorithm itself, but is nonetheless a function performed by the fairness machine. The number of milliseconds that pass without receiving a fairness message from the neighboring stations is measured. When this time exceeds the keepalive timeout value, then a keepalive event is triggered, which may generate a protection event. The timer may have a different value on either span.

Examples

The following example shows how to set the keepalive timer to 5 milliseconds:

Related Commands

rpr-ieee protection sonet holdoff-timer

To specify a delay before a protection response is sent, use the rpr-ieee protection sonet holdoff-timer command in interface configuration mode. To disable the hold-off timer, use the no form of this command.

rpr-ieee protection sonet holdoff-timer time [east | west]

no rpr-ieee protection sonet holdoff-timer time [east | west]

Syntax Description

time

Specifies the delay before a protection response is sent. Values range from 0 to 20, in units of 10 milliseconds. The default is 0.

east

(Optional) Specifies that the configuration is for the east span. If no span is specified, the configuration is set for both the east and west spans.

west

(Optional) Specifies that the configuration is for the west span.

Defaults

0 milliseconds

Command Modes

Interface configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

A protection response to Layer 1 failure events (such as a signal failure or signal degradation) can be delayed by configuring the hold-off timer. A higher value for this timer causes a protection response to be delayed, avoiding link errors that persist long enough to be detected by protection but short enough to avoid costs of protecting the span. This higher value can result in higher traffic loss, however. The default for this timer is 0 milliseconds.

Examples

Related Commands

Displays the RPR protection, topology, counters, and transit information for an RPR interface.

rpr-ieee protection pref jumbo

To enable handling of jumbo frames, use the rpr-ieee protection pref jumbo command in installation configuration mode. To disable this option, use the no form of this command.

rpr-ieee protection pref jumbo

no rpr-ieee protection pref jumbo

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release

Modification

12.0(30)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

This command enables handling of frames in excess of the standard 1500 bytes, up to a maximum size of 9100 bytes. If you configure the MTU to be jumbo (9100 bytes) it does not take effect unless all stations on the ring are configured to support jumbo frames. A warning message is displayed if the MTU is inconsistent between stations. A message is also displayed when the MTU value is changed.

Examples

The following example enables handling of jumbo frames:

Router(config-if)# rpr-ieee protection pref jumbo

Related Commands

Displays the RPR protection, topology, counters, and transit information for an RPR interface.

rpr-ieee protection pref wrap

To enable the preference of wrapping protection instead of steering, use the rpr-ieee protection pref wrap command in installation configuration mode. To remove wrapping preference, use the no form of this command.

rpr-ieee protection pref wrap

no rpr-ieee protection pref wrap

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release

Modification

12.0(30)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

Stations can be made to prefer wrapping protection instead of steering, as long as conditions permit. Such a station use wrapping for protection only if every other station in the ring is also wrap preferred. This option is disabled by default to prefer steering. No warning message is displayed if the ring protection mode between stations is inconsistent.

Examples

Related Commands

Displays the RPR protection, topology, counters, and transit information for an RPR interface.

rpr-ieee protection request forced-switch

To initiate a forced switch, use the rpr-ieee protection request forced-switch command in interface configuration mode. To disable a forced switch, use the no form of this command.

rpr-ieee protection request forced-switch

no rpr-ieee protection request forced-switch

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

A forced switch precedes all other failure events on a ring, for the span on which it is configured. The operation protects the span indicated by the command. In the case of steering, forwarding uses only the topology list for the opposite span. In the case of wrapping, the other span becomes wrapped.

A forced switch is saved in the router configuration.

Examples

The following example shows the initiation of a forced switch on the east span:

Displays the RPR protection, topology, counters, and transit information for an RPR interface.

rpr-ieee protection request manual-switch

To initiate a manual switch, use the rpr-ieee protection request manual-switch command in interface configuration mode. To disable the manual switch, use the no form of this command.

rpr-ieee protection request manual-switch

no rpr-ieee protection request manual-switch

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

A manual switch behaves similarly to a forced switch, in that it coerces a reaction from the protection system. The difference is that this configuration can be usurped by higher-level requests detected on the configured or opposite span.

A manual switch is not saved in the router configuration.

Examples

The following example shows the initiation of a manual switch on the west span:

Syntax Description

Specifies a bit error rate (10 to the minus n), where n can range from 4 to 9.

east

(Optional) Specifies that the configuration is for the east span. If no span is specified, the configuration is set for both the east and west spans.

west

(Optional) Specifies that the configuration is for the west span.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

For SONET-based devices, RPR can set the threshold at which a protection event occurs for a signal failure or signal degradation (sf-ber or sd-ber). This feature can be configured differently on either span.

Examples

The following example shows how to set the signal degradation threshold to 10-6:

Router(config-if)# rpr-ieee protection sonet threshold sd-ber 6

rpr-ieee protection timer

To control the frequency of the transmission of protection requests, use the rpr-ieee protection timer command in interface configuration mode. To restore the default timer value, use the no form of this command.

rpr-ieee protection timer {fasttime | slowtime}

no rpr-ieee protection timer {fasttime | slowtime}

Syntax Description

fast time

Specifies the value of the fast protection timer, which ranges from 1 to 20 milliseconds. The default is 10.

slow time

Specifies the value of the slow protection timer, which ranges from 1 to 10 in units of 100 milliseconds. The default is 1 in units of 100 milliseconds.

Defaults

fast—10 milliseconds; slow—1x100 milliseconds

Command Modes

Interface configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

Protection messages are sent based on the intervals of two timers. These timers apply under different circumstances:

•Fast timer—Immediately after a protection event occurs, a fast protection timer is used. This timer is configured between 1 and 20 milliseconds to cause a rapid acknowledgement of the protected state on neighbors. A finite number of packets are sent at this frequency after the event. The default for this timer is 10 milliseconds.

•Slow timer—Between protection events, the slow timer communicates the current protection state of the ring. This timer is configured from 1 to 10 in units of 100 milliseconds. The default is 10, which represents 100 milliseconds.

Examples

The following example shows how to set the fast protection timer to 10 milliseconds:

Related Commands

rpr-ieee protection wtr-timer

To configure the wait-to-restore timer, use the rpr-ieee protection wtr-timer command in interface configuration mode. To restore the default of the timer, use the no form of this command.

rpr-ieee protection wtr-timer {time | never}

no rpr-ieee protection wtr-timer {time | never}

Syntax Description

time

Specifies a value of the wait-to-restore timer in seconds. Values range from 0 to 1440. The default is 10.

never

Specifies that protection is never restored (nonrevertive mode).

Defaults

10 seconds

Command Modes

Interface configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

When a failure is de-asserted on a span, a wait-to-restore timer defines how long before the span becomes unprotected. This timer can be used to protect against false negatives in the detection of the failure status, and thus avoid protection-flapping by using larger values. Smaller values result in faster recovery times, however.

Examples

The following example shows how to set the wait-to-restore timer to 20 seconds:

Router(config-if)# rpr-ieee protection wtr-timer 20

Related Commands

rpr-ieee shutdown

To shut down an RPR interface by entering a forced switch on the span, use the rpr-ieee shutdown command in interface configuration mode. To remove the forced switch on the span, use the no form of this command.

rpr-ieee shutdown {east | west}

no rpr-ieee shutdown {east | west}

Syntax Description

east

Specifies that the configuration is for the east span.

west

Specifies that the configuration is for the west span.

Defaults

Interface not shutdown

Command Modes

Interface configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

This rpr-ieee shutdown command is an abbreviated form of the rpr-ieee protection request forced-switch interface configuration command that enters a forced-switch request on the span. The long form, rpr-ieee protection request forced-switch, appears in the show configuration output.

Examples

The following example shows how to disable the RPR interface on the east span:

Related Commands

rpr-ieee tx-traffic idle

To configure transmission of idle packets at various rates to accommodate neighbors that are not capable of higher transmission rates, use the rpr-ieee tx-traffic idle command. Use the no form of this command to disable transmission of idle packets.

Syntax Description

Specifies whether any idle packets are sent at all. The default operation is enabled.

threshold threshold

Specifies the transit queue vacancy under which fewer idle packets are transmitted, allowing for the transit queue to drain faster. A higher threshold allows the idle packet transmit behavior to change sooner. The default vacancy threshold is 1 MTU.

east

(Optional) Specifies that the configuration is for the east span. If no span is specified, the configuration is set for both the east and west spans.

west

(Optional) Specifies that the configuration is for the west span.

Defaults

Enabled with a threshold of 1 MTU.

Command Modes

Interface configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

The idle packet transmitter approximately synchronizes rates between stations by padding traffic with idle packets transmitted at a certain rate. Idle packets are transmitted only to the neighbor, and therefore do not take up transit queue space. If the transit queue vacancy of the local station falls below the configurable idle threshold, fewer idle packets are transmitted by the local station to give more transmission time to drain the queue. This rate synchronization is used for extreme congestion to prevent packet drops in the transit queue.

Examples

The following example shows how to set the idle threshold to 10000 MTU on the east span:

Router(config-if)# rpr-ieee tx-traffic idle threshold 10000 east

Related Commands

Displays the configured values for the rate manipulators on various classes of traffic.

rpr-ieee tx-traffic rate-limit

To configure the amount of high- and low-priority traffic being transmitted from the router onto the RPR ring, use the rpr-ieee tx-traffic command in interface configuration mode. Use the no form of this command to remove the TX traffic rate from the configuration.

Syntax Description

Limits the rate of service class A1. The default rate allocation is 10 Mbps.

medium

Limits the rate of service class B-CIR. The default allocation is 10 Mbps.

low

Limits the rate of service classes B-EIR and C. The default rate allocation is full bandwidth.

reserved

Reserves bandwidth for the highest-priority traffic, known as service class A0. The default rate allocation is 0 Mbps.

rate

Specifies the average rate allocation for a service class in Mbps. OC-48 interface values must be in increments of 1 Mbps in the range of 0 to 2488.

east

(Optional) Specifies that the configuration is for the east span. If no span is specified, the configuration is set for both the east and west spans.

west

(Optional) Specifies that the configuration is for the west span.

Defaults

0 Mbps for reserved; 10 Mbps for high; full bandwidth for low; 10 Mbps for medium

Command Modes

Interface configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

The different priorities of traffic can be configured with rate limiters and prescribed specific bandwidths. This configuration may differ on the east and west spans, or can be configured equally on both.

The highest-priority traffic, known as service class A0, can reserve a portion of total ringlet bandwidth using the reserved keyword. This reservation is propagated throughout the ringlet, and all stations recognize the bandwidth allocation cumulatively. The default allocation is 0 megabits per second.

Service class A1 is configured as high-priority traffic in excess of the A0 bandwidth reservation, and can be rate-limited using the high tx-traffic rate limiter. The default allocation is 10 megabits per second.

The medium transmission traffic rate limiter allows a certain amount of traffic to be added to the ringlet that is not subject to fairness eligibility, but must compete for the unreserved bandwidth with other traffic of the same service class. This traffic is committed information rate (B-CIR) traffic. Some interfaces may not support this class of traffic, so this command may not be available on all RPR interfaces. The default allocation is 10 megabits per second.

The low tx-traffic rate limiter restricts the amount of bandwidth that service classes B-EIR and C may use on the ringlet. This traffic class is fairness eligible and thus this value impacts the effectiveness of the fairness algorithm. The default allocation is full bandwidth.

Examples

The following example shows how to set the high-priority rate limit to 20 Mbps on the west span:

Router(config-if)# rpr-ieee tx-traffic rate-limit high 20 west

Related Commands

Displays the configured values for the rate manipulators on various classes of traffic.

rpr-ieee tx-traffic strict

To specify that traffic be flushed after a topology change, such as a protection event, until the topology stabilizes, use the rpr-ieee tx-traffic strict command. Use the no form of this command to specify not to drop traffic in case of a protection event.

rpr-ieee tx-traffic strict

no rpr-ieee tx-traffic strict

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release

Modification

12.0(30)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

The default TX traffic mode is relaxed, which means that traffic is redirected based on the protection setting as quickly as possible. In some cases, relaxed traffic arrives out of order or is duplicated, but results in less traffic loss during node recovery than strict traffic mode.

Strict traffic is flushed from the ring until the ring topology recovers and is stable. In this way, a possible duplication or re-ordering of strict traffic is prevented. Strict traffic mode results in greater traffic loss than relaxed mode during the topology change.

The traffic mode is configured as relaxed or strict for the router.

Examples

The following example shows how to set the traffic mode to strict:

Router(config-if)# rpr-ieee tx-traffic strict

Related Commands

Command

Description

show controllers rpr-ieee

To display RPR controller information, use the show controllers rpr-ieee command in privileged EXEC mode.

show controllers rpr-ieee [slot/port] [details] [transceiver]

Syntax Description

slot/port

(Optional) Specifies the chassis slot number and port number of a specific RPR interface. If these are not specified, the command displays information for all RPR interfaces.

details

Provides additional information about the controller in the output.

transceiver

Displays the status of the SFP module used in the specified RPR port.

Defaults

No default behavior or values

Command Modes

Privileged EXEC

Command History

Release

Modification

12.0(29)S

This command was introduced.

12.0(30)S

Support for the optional transceiver keyword was added.

Usage Guidelines

This command applies to RPR interfaces only.

Starting in IOS Release 12.0(30)S, use the transceiver keyword to display additional information about the status of the small form-factor pluggable (SFP) module used in an RPR port.

Examples

The following example shows sample output from this command:

Router# show controllers rpr-ieee 1/1

Interface RPR-IEEE1/1

Hardware is OC48 RPR-IEEE

RPR-IEEE1/1 - West Span (Ringlet0 RX, Ringlet1 TX)

SFP Module West is VALID

OPTICS

TX power -4 (+/- 3) dBm

RX power -5 (+/- 3) dBm

No Active Alarms

No Active Warnings

SECTION

LOF = 0 LOS = 0 BIP(B1) = 0

LINE

AIS = 0 RDI = 0 FEBE = 0 BIP(B2) = 0

PATH

AIS = 0 RDI = 0 FEBE = 0 BIP(B3) = 0

LOP = 0 NEWPTR = 0 PSE = 0 NSE = 0

Active Defects: None

Active Alarms: None

Alarm reporting enabled for: SLOS SLOF PLOP

Framing : SONET

Rx SONET/SDH bytes: (K1/K2) = 0/0 S1S0 = 0 C2 = 0x16

Tx SONET/SDH bytes: (K1/K2) = 0/0 S1S0 = 0 C2 = 0x16 J0 = 0x1

Clock source : Internal

Framer loopback : None

Path trace buffer : Stable

Remote hostname : EAST-D

Remote interface: RPR-IEEE1/1

Remote IP addr : 1.1.1.1

Remote side id : EAST

BER thresholds: SF = 10e-3 SD = 10e-6

IPS BER thresholds(B3): SF = 10e-3 SD = 10e-6

TCA thresholds: B1 = 10e-6 B2 = 10e-6 B3 = 10e-6

RPR-IEEE1/1 - East Span (Ringlet1 RX, Ringlet0 TX)

SFP Module East is VALID

OPTICS

TX power -4 (+/- 3) dBm

RX power -5 (+/- 3) dBm

No Active Alarms

No Active Warnings

SECTION

LOF = 0 LOS = 0 BIP(B1) = 0

LINE

AIS = 0 RDI = 0 FEBE = 0 BIP(B2) = 0

PATH

AIS = 0 RDI = 0 FEBE = 0 BIP(B3) = 0

LOP = 0 NEWPTR = 0 PSE = 0 NSE = 0

Active Defects: None

Active Alarms: None

Alarm reporting enabled for: SLOS SLOF PLOP

Framing : SONET

Rx SONET/SDH bytes: (K1/K2) = 0/0 S1S0 = 0 C2 = 0x16

Tx SONET/SDH bytes: (K1/K2) = 0/0 S1S0 = 0 C2 = 0x16 J0 = 0x1

Clock source : Internal

Framer loopback : None

Path trace buffer : Stable

Remote hostname : WEST-D

Remote interface: RPR-IEEE1/1

Remote IP addr : 1.1.1.3

Remote side id : WEST

BER thresholds: SF = 10e-3 SD = 10e-6

IPS BER thresholds(B3): SF = 10e-3 SD = 10e-6

TCA thresholds: B1 = 10e-6 B2 = 10e-6 B3 = 10e-6

The following example shows sample output from this command using the transceiver keyword:

show rpr-ieee counters

To display counters for each of the various service classes on each RPR span, use the show rpr-ieee counters command in privileged EXEC mode.

show rpr-ieee counters [rpr-ieeeslot/port]

Syntax Description

rpr-ieeeslot/port

(Optional) Specifies the chassis slot number and port number of a specific RPR interface. If these are not specified, the command displays information for all RPR interfaces.

Defaults

No default behavior or values

Command Modes

Privileged EXEC

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

Traffic counters are collected from various sources in the interface, and are displayed using the counters command. This command shows received, transited, and transmitted quantities of each of the various service classes, and on each span. Receive errors are also indicated for each span.

Syntax Description

(Optional) Displays a report on recent congestion history. The local and downstream congestion is displayed for both ringlets

intervals

(Optional) Specifies the number of 15-minute intervals to display. Values can be 1 to 96, which corresponds to 24 hours.

rpr-ieeeslot/port

(Optional) Specifies the chassis slot number and port number of a specific RPR interface. If these are not specified, the command displays information for all RPR interfaces.

details

(Optional) Besides the normal information displayed by the show rpr-ieee fairness command, the details keyword provides the coefficients used, more expressions of the configured and detected rates, and transit queue information.

Defaults

No default behavior or values

Command Modes

Privileged EXEC

Command History

Release

Modification

12.0(29)S

This command was introduced.

12.0(30)S

The history keyword was added.

Usage Guidelines

This command applies to RPR interfaces only.

The fairness system uses a large quantity of input to determine its behavior. This input and some results of the fairness algorithm, can be displayed using this command. Information for both directions is always shown.

The history keyword reports the fairness state in the last 96 fifteen-minute intervals (a total of 24 hours). This report provides a good indication of ring load and bandwidth utilization on a station-by-station basis. Note that due to the way the algorithm works, you never see 100-percent congestion. Any congestion over 80 percent can be considered as constant congestion.

Examples

The following example shows sample output from this command:

Router# show rpr-ieee fairness

IEEE 802.17 Fairness on RPR-IEEE1/1:

Bandwidth: 2488320 kilobits per second

Station using aggressive rate adjustment.

Westbound Tx (Ringlet 1)

Weighted Fairness:

Local Weight: 0 (1)

Single-Choke Fairness Status:

Local Congestion:

Congested? No

Head? No

Downstream Congestion:

Congested? No

Tail? No

Received Source Address: 0001.0001.0001

Reserved Rate:

0 Kbps

Unreserved Rate:

2488320 Kbps

Eastbound Tx (Ringlet 0)

Weighted Fairness:

Local Weight: 0 (1)

Single-Choke Fairness Status:

Local Congestion:

Congested? No

Head? No

Downstream Congestion:

Congested? No

Tail? No

Received Source Address: 0003.0003.0003

Reserved Rate:

0 Kbps

Unreserved Rate:

2488320 Kbps

The following example shows sample output from this command when the details keyword is used:

Router# show rpr-ieee fairness details

IEEE 802.17 Fairness on RPR-IEEE1/1:

Bandwidth: 2488320 kilobits per second

Station using aggressive rate adjustment.

Westbound Tx (Ringlet 1)

Weighted Fairness:

Local Weight: 0 (1)

Single-Choke Fairness Status:

Local Congestion:

Congested? Yes

Head? No

Local Fair Rate:

Approximate Bandwidth: 1190000 Kbps

29750 normalized bytes per aging interval

59500 bytes per ageCoef aging interval

Downstream Congestion:

Congested? No

Tail? No

Received Source Address: 0001.0001.0001

Received Fair Rate:

Approximate Bandwidth: FULL RATE

65535 normalized bytes per aging interval

Reserved Rate:

0 Kbps

0 bytes per aging interval

Unreserved Rate:

2488320 Kbps

31104 bytes per aging interval

Allowed Rate:

Approximate Bandwidth: 2488320 Kbps

31104 bytes per aging interval

Allowed Rate Congested:

Approximate Bandwidth: 2487040 Kbps

31088 bytes per aging interval

TTL to Congestion: 255

Total Hops Tx: 2

Advertised Fair Rate:

Approximate Bandwidth: 1179600 Kbps

29490 normalized bytes per aging interval

14745 bytes per aging interval

Eastbound Tx (Ringlet 0)

Weighted Fairness:

Local Weight: 0 (1)

Single-Choke Fairness Status:

Local Congestion:

Congested? Yes

Head? Yes

Local Fair Rate:

Approximate Bandwidth: 1188640 Kbps

29716 normalized bytes per aging interval

59432 bytes per ageCoef aging interval

Downstream Congestion:

Congested? No

Tail? No

Received Source Address: 0003.0003.0003

Received Fair Rate:

Approximate Bandwidth: FULL RATE

65535 normalized bytes per aging interval

Reserved Rate:

0 Kbps

0 bytes per aging interval

Unreserved Rate:

2488320 Kbps

31104 bytes per aging interval

Allowed Rate:

Approximate Bandwidth: 2488320 Kbps

31104 bytes per aging interval

Allowed Rate Congested:

Approximate Bandwidth: 2487040 Kbps

31088 bytes per aging interval

TTL to Congestion: 255

Total Hops Tx: 2

Advertised Fair Rate:

Approximate Bandwidth: FULL RATE

65535 normalized bytes per aging interval

32767 bytes per aging interval

The following example shows sample output from this command with the history keyword and 3 intervals displayed:

Time interval for display purposes. The output displays up to 96 fifteen-minute intervals, which corresponds to the last 24 hours.

Time

Time at the beginning of the interval.

Aging Intervals (Congested)

Computation of the number of aging intervals that experienced congestion. A minute has 600,000 aging intervals.

Aging Intervals (Total)

Total number of aging intervals in the associated time interval.

Seconds Congested

Number of congested seconds that correspond to the congested aging intervals. A second has 10,000 aging intervals.

Seconds Total

Total number of seconds in the associated time interval.

Percent Congested

Number of congested aging intervals divided by the number of aging intervals in the time interval.

Note Due to the nature of the fairness algorithm, it is not possible to report 100-percent congestion for any interval. If this command reports congestion above 80 percent, then the station is near peak congestion for that interval and can be considered to be at maximum fairness congestion.

Defaults

No default behavior or values

Command Modes

Privileged EXEC

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

Use this command to view the configured values for the rate manipulators on the various classes of traffic. There are rate limiters for classes A0 (or reserved), A1, B-CIR, and B-EIR and C. Some interfaces do not support class B on transmit, so only the other three are displayed.

Examples

The following example shows sample output from this command:

Router# show rpr-ieee rate-limit

Rate Limit Information for Interface RPR-IEEE1/1

West Span:

Reserved Bandwidth (Class A0): 0 Mbps

Rate Limiter High (Class A1): 10 Mbps

Rate Limiter Medium (Class B-CIR): 10 Mbps

Rate Limiter Low (Class B-EIR, C): full

East Span:

Reserved Bandwidth (Class A0): 0 Mbps

Rate Limiter High (Class A1): 10 Mbps

Rate Limiter Medium (Class B-CIR): 10 Mbps

Rate Limiter Low (Class B-EIR, C): full

The following example shows sample output from this command when the details keyword is used:

router# show rpr-ieee rate-limit details

Rate Limit Information for Interface RPR-IEEE1/1

West Span:

Reserved Bandwidth (Class A0): 0 Mbps

Rate Limiter High (Class A1): 10 Mbps

Rate Limiter Medium (Class B-CIR): 10 Mbps

Rate Limiter Low (Class B-EIR, C): 2488 Mbps

East Span:

Reserved Bandwidth (Class A0): 0 Mbps

Rate Limiter High (Class A1): 10 Mbps

Rate Limiter Medium (Class B-CIR): 10 Mbps

Rate Limiter Low (Class B-EIR, C): 2488 Mbps

Service Type: Relaxed

Idle Shaper is Enabled

Transmit at 500 packets per million when PTQ vacancy above 18432 bytes

Transmit at 250 packets per million when PTQ vacancy below 18432 bytes

show rpr-ieee topology

To identify the stations on the ringlet, use the show rpr-ieee topology command in privileged EXEC mode.

show rpr-ieee topology [rpr-ieeeslot/port] [details]

Syntax Description

rpr-ieeeslot/port

(Optional) Specifies the chassis slot number and port number of a specific RPR interface. If these are not specified, the command displays information for all RPR interfaces.

details

(Optional) Besides the normal information displayed by the show rpr-ieee topology command, the details keyword displays more information about the stations on the ring.

Defaults

No default behavior or values

Command Modes

Privileged EXEC

Command History

Release

Modification

12.0(29)S

This command was introduced.

Usage Guidelines

This command applies to RPR interfaces only.

This command provides information on the local station, its neighbors, and the general state of the ring. Packets sent to communicate topology information are constructed using data from various sources, such as configured preferences, cumulative reserved bandwidth, protection states, and station name. This information is displayed for the local station and every active station from which a topology message has been received.

Examples

The following example shows sample output from this command:

Router# show rpr-ieee topology

Ring Topology: CLOSED (STABLE)

Configured protection mode: STEERING

Jumbo preference: NOT SET (ring doesn't support JUMBOS)

Number of nodes on

ringlet0: 3 ringlet1: 3

Checksum: 0x00180090 (VALID)

West Neighbor Checksum: 0x00180090 (VALID)

East Neighbor Checksum: 0x00180090 (VALID)

Index (Ri 0) MAC IP Address Edge W/E Request W/E

1 0001.0001.0001 1.1.1.1 NO/NO IDLE/IDLE

2 0003.0003.0003 1.1.1.3 NO/NO IDLE/IDLE

3 0002.0002.0002 1.1.1.2 NO/NO IDLE/IDLE

Index (Ri 1) MAC IP Address Edge W/E Request W/E

1 0003.0003.0003 1.1.1.3 NO/NO IDLE/IDLE

2 0001.0001.0001 1.1.1.1 NO/NO IDLE/IDLE

3 0002.0002.0002 1.1.1.2 NO/NO IDLE/IDLE

Following is sample output from this command when the details keyword is used:

Aggressive—Default ramp rate for the fairness algorithm. Aggressive mode ramps up as quickly as possible when bandwidth is available and ramps down as quickly as possible when congestion occurs. This fast ramping can result in unstable traffic behavior in very bursty traffic scenarios.

BER—Bit Error Rate from SONET Standard (GR-253). The number of coding violations detected in a unit of time, typically 1 second.

C—Service class for lowest-priority traffic.

CIR—Committed information rate.

Closed ring—Idle ring.

Conservative—Optional ramp rate for the fairness algorithm. Conservative mode ramps up in stages (over a few hundred ms) when bandwidth is available and ramps down in stages (over a few hundred mn) when congestion occurs. This slow ramping can result in slightly lower bandwidth utilization, but is more applicable in very bursty traffic scenarios.

DPT—Dynamic Packet Transport. Creates dual, counter-rotating fiber rings. Both fibers concurrently transport both data and control traffic, and use Intelligent Protection Switching (IPS) that provides proactive performance monitoring, event detection, and rapid self-healing, and restores IP service after fiber facility or node failures. Also called SRP.

East—Span on which RPR transmits on ringlet 0.

Edge—Protection edge in an open ring

EIR—Excess information rate.

Exceed action—Action to take on packets above the rate allowed by the rate limit.

Excess burst size—Bytes allowed in a burst before all packets exceed the rate limit.

Forced switch—Takes precedence over all other failure events on a ring, for the span on which it is configured. The operation protects the span indicated by the command. In the case of steering, forwarding uses only the topology list from the opposite span. In the case of wrapping, the other span becomes wrapped. A forced switch is saved in the configuration.

Jumbo—Frames in excess of the standard 1500 bytes, up to a maximum size of 9100 bytes.

MAN—Metropolitan area network.

Manual switch—Coerces a reaction from the protection system. The difference between a manual and a forced switch is that this configuration can be usurped by higher-level requests detected on the configured or opposite span. A manual switch is not saved in the configuration.

Normal burst size—Bytes allowed in a burst before some packets will exceed the rate limit. Larger bursts are more likely to exceed the rate limit.

Ringlet—One of two unidirectional, counter-rotating rings that connect the stations in an RPR topology. Ringlet0 transverses from east to west; ringlet 1 transverses from west to east.

RPR—Resilient Packet Ring, as defined in IEEE 802.17.

Signal degradation—Enters automatic protection switch wraps on a span when it is invoked by a media signal degrade, such as an excessive bit error rate.

Signal failure—Enters automatic protection switch wraps on a span when it is invoked by a media signal failure or SRP keepalive failure. The signal failure protection switch wrap remains in effect until the event is repaired.

SRP—Spatial Reuse Protocol.

Steering—Ring protection mode where stations that detect a failed span notify all other stations in the ring. Each individual station is then responsible for "steering" traffic away from the failed span to reach the destination.

Synchronous Digital Hierarchy (SDH)—European standard that defines a set of rate and format standards that are transmitted using optical signals over fiber. SDH is similar to SONET, with a basic SDH rate of 155.52 Mbps, designated at STM-1.

Synchronous Optical Network (SONET)—High-speed synchronous network specification developed by Bellcore and designed to run on optical fiber. STS-1 is the basic building block of SONET. Approved as an international standard in 1988.

Wait-to-restore (WTR)—Invokes a waiting period after the working channel meets the restoration criteria after a signal failure or signal degradation disappears. The wait-to-restore period prevents protection switch oscillations.

West—Span on which RPR transmits on ringlet 1.

Wrapping—Ring protection mode where the two stations on either end of a failed span react by "wrapping" traffic back onto the opposite ringlet to reach the destination.